The number of fire-related fatalities and amount of property damage has significantly declined worldwide in recent decades as legislation has forced a variety of polymeric materials to be rendered flame retardant (FR), but as new fire risk scenarios occur, the need for new flame retardants continues unabated despite the downward trend in US fire losses. As of 1998, flame retardants were second only to plasticizers in terms of quantity added to plastics. Brominated compounds continue to be the most commonly used flame retardants, but environmental concerns regarding brominated FR additives have led to significant research into the use of other flame retardant chemistries and approaches, including polymer nanocomposites prepared from more environmentally benign nanoparticles like clays and carbon nanotubes. These polymer nanocomposites typically exhibit reduced mass loss and heat release rates, along with anti-dripping behavior, all of which is believed to be due to the formation of a barrier surface layer in the case of clay and a gel-like network in the case of nanotubes. Despite this improved thermal behavior, adding these particles is known to increase viscosity and modulus of the final polymeric material, making industrial processing difficult. These adverse side effects of viscosity make their use in protection of highly flammable flexible foams and fabrics prohibitive, and create a vitally important need for an alternative technology. In the proposed work, thin nanocomposite coatings (less than one micron thick) made with nanoparticles and/or polymers, uniformly applied to the three-dimensional surface of fibers in fabrics (and fill), will be studied to provide enhanced flame retardancy. This novel coating system is made possible using the layer-by-layer (LbL) assembly deposition technique.
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